Transformer



Dec. 31, 1929. F. c. WAPPLER TRANSFORMER Filed March 16, 1927 Patented Dec. 31, 1929 FREDERICK CHARLES WAPPLER, OF NEW YORK, N. Y.

TRANSFORMER Application filed March 16, 1927. Serial No. 175,687.

My present invention relates generally to transformers, and has particular reference to a core type of transformer especially designed for simple and expeditious association 6 with an electric outlet box of ordinary type.

One object of my invention is to provide a transformer primarily adapted for use with miniature electric lamps employing about 2-12 volts, the transformer being designed 10 to render available the ordinary house current of about 110 volts.

With this object in view, the features of my invention lie in so constructing the trans former as to render it suitable and easily useable for its contemplated purpose. One feature lies in providing a cylindrical casing having a diameter in the neighborhood of 1 ,4 inches and being provided with a pair of contact prongs extending from one end thereof for insertion into the openings in any ordinary outlet box. Other features of my invention lie in so constructing the constituent parts of the transformer as to permit their compact yet eificient arrangement within a casing of the character mentioned, while at the same time maintaining the total weight of the device extremely low.

Although the various features of construction render my device particularly applicable for the employment mentioned above, nevertheless it will be understood that as to certain features of my invention, an application of this character is not essential.

Thus, certain features of my invention relate to the construction of a shell-type transformer which could easily be associated with different casings, contact prongs, and the like. In this connection, it is a feature of my invention to provide a core having a loop portion made up of laminations and a central complementary bar portion made up of similar aminations, the laminations of the bar portion being arranged perpendicularly to those of the loop portion.

It is a particular feature of my invention to provide an independent bar portion of the character mentioned, whereby the latter may be associated with the loop portion after suitable windings have been arranged thereon. r

Another feature of my invention lies in providing complementary constituent portions whose independent manufacture is extremely simple and inexpensive and whose mutual association and assembly may be effected in an extremely simple manner, as by frictional engagement.

These features, and others, of my invention, make it possible to construct a complete device of the character in contemplation by the employment of simple and inexpensive constituent parts and with a minimum amount of effort and time.

Another feature of my invention lies in associating with the casing a controlling rheostat comprising a manually controllable lever or arm extending out of the casing in an extremely practical manner whereby manipulation of the arm may control the exact output voltage desired.

For the attainment of the foregoing objects and such other objects as may hereinafter appear or be pointed out, I have illustrated one embodiment of my invention in the accompanying drawings in which- Fig. 1 is a perspective view of a complete transformer, constructed in accordance with my invention, and shown in association with an ordinary outlet box and with conducting Wires leading to a miniature lamp of the character mentioned;

Fig. 2 is an exploded view of the constituent portions of my device, certain of these portions being shown in semi-assembled condition; 35

Fig. 3 is an elevational view of certain interior portions of my device, these portions being shown in assembled condition and depicting one stage in the process of construction; and

Fig. 4 is a longitudinal cross-sectional view taken substantially along the line 44 of Fig. 1, showing the general interior arrangement of the elements.

In Fig. 1 I have shown an outlet box 10 of usual construction, the contact prongs of my transformer being positioned within the openings of the outlet box so as to support the device in an outwardly projecting manner as illustmted.

The device is substantially cylindrical in shape, comprising a cylindrical or tubular body portion 36 and end walls 38 and 43, the wall 38 having suitable contact prongs fixedly associated therewith, the prongs extending from the end thereof in a manner which permits them to be inserted in the outlet box openings as shown in Fig. 1. With the end 43 I associate two contact terminals 14 designed to receive lead wires 15, the terminals 14 being of any suitable type or construction to permit easy application and removal of the lead wires.

The construction of my device can best be explained by reference to Fig. 2 and by a description of the steps leading up to the finished construction. I provide first a core portion in the form of a substantially rectangular loop 16, this portion bein made up of suitable laminations of looped orm. To cooperate with and complement the loo portion 16, I provide a central or bar portlon 17 consisting of a series of substantially rectangular laminations, each of the latter having a width substantially equal to the distance from front to back of the loop portion 16. It will be observed that the bar portion 17 is entirely independent of the loop portion 16, the mutual association of these portions to complete a shell-type transformer core being subsequently effected.

I then proceed to constitute a spool of the bar 17 and I accomplish this by frictionally applying thereto two preferably circular washers 18 having rectangular openings therein to permit frictional application thereof over the opposite ends of the bar 17. Although not absolutely essential, I prefer to provide struck-up portions 19 in the outside laminations of the bar 17, these portions being designed to facilitate the proper predetermined positioning of the washers 18 upon the bar 17.

Upon the spool thus constituted, I wind the necessary coils of wire for providing a primary coil or winding and a secondary winding, the discs 18 being suitably apertured to permit the passage therethrough of the ends of the windings. The ends 20 are those of the primary winding and the ends 21 are those of the secondary winding.

Having thus completed the winding of the coils, the entire wound spool structure is ready for association with the loop portion 16. The bar 17 is made of such a length that it may be frictionally forced through opposite ends of the loop portion. I-am enabled to take further advantage of the independent construction of the central bar 17 by applying it to the loop portion in a manner which arranges the respective laminations in perpendicular planes. I have found the efliciency of the transformer to be increased by a construction of this character.

To further enhance the snug and compact arrangement, the washers 18 are made of diameters substantially equal to the distance between the op osite sides of the loop 16, and after the bar 17 is jammed into position, the spool will occupy a position relative to the loop 16 as shown in Fig. 3. The essential electrical portions of the transformer are thus completed, a compact and efliciently constructed shell-type transformer being provided.

The last step in the construction lies in providing end discs upon the opposite ends of the core, these discs being preferably parallel and of a diameter substantially equal to the overall width of the core. The end por tions 22 of the core are laid along diameters of the discs 23 and 24, and a firm attachment is preferably effected by means of clamps 25 and bolts 26.

The clamps 25 are four in number, one pair being employed for each end 22 of the core. Each clamp may comprise a U-shaped stamping having laterally extending ends with threaded openings therein, these openings being arranged and constructed to receive the ends of the bolts 26 extending inwardly through the discs 23 and 24. The bolts 26 are arranged in a countersunk manner within the discs, as clearly shown in connection with the disc 24 of Fig. 2.

Although not essential, I prefer to construct the clamps 25 so that the cross piece or center of the U is slightly narrower than the balance of the clamp. In this way, the clamps may first be positioned as shown at the top of Fig. 3 and thereafter brought together before being associated with the corresponding end disc. In the bottom portion of Fig. 3, the clamps have been brought together, and it will be observed that the narrower width of the central portion of each clamp provides portions or tabs which engage the extreme end portions of the bar 17, thus assuring the proper retention of the bar in its position.

In contemplation of the balance of the assembly, the discs 23 and 24 are further constructed as follows, prior to their association with the core. In the disc 23 a pair of threaded openings 27 are provided, these openings lying along a diameter at right angles to the position assumed by the end 22 of the core. Adjacent to each of the openings 27 is a smaller opening 28 to permit the passage therethrough of wires. Lying along a similar diameter 0 the disc 24 are two bolts 29 and 30 whose heads are slightly countersunk in the inner surface of the disc and whose threaded ends project outwardly as clearly shown in Fig. 2. Both discs 23 and 24 are of insulatin material, and mounted upon the bolt 29 is a small washer 31 of conducting material whereas a similar washer 32 of insulating material is similarly associated with the bolt 30. The. urpose of these washers will be presently ascribed.

The disc 24 is also provided with a contact arm 33 lying along a diameter ofthe outside surface of the disc 24 and pivoted at the center 34 of the disc. Adjacent to this central pivot is a small opening 35 for the passage of a wire. 7

The discs 23 and 24 being so prepared, and being thereupon fixedly associated with the 'core as indicated in Fig. 3, the casin is then ready for application to the assembly thus produced. The casing comprises a tubular body portion 36 having a diameter and length which permits it to snugly enclose the entire assembl including the end discs 23 and 24. The end adapted to be associated with the disc 24 is provided with two diametrically opposed extensions 37 of depths equal to the depths of the washers 31 and 32.

After the tubular portion 36 has been applied, the end walls of the casing are applied to complete the structure.

The end walls are both of diameters which are slightly greater than the diameter of the tube 36 so that their attachment to the discs 23 and 24 will serve to hold the tube 36 in position between them. The end 38, associated with'the disc 23, is provided with a pair of openings 39 designed to register with the openings 27. The openings 39 are countersunk and a suitable passageway is provided for the ends 20 to extend outwardly through the holes 28 and into the countersunk portions of the end 38. Thereafter, washers 40 are laid into the openings 39 and over the ends 20, and the contact prongs 41 having threaded ends 42 are then screwed into the openings 27, thus securely fastening the end Wall 38 in position and at the same time establishing contact through the washers 40 with the ends 20 of the primary, winding. ,These prongs 41 are constructed as shown iii Fig. 2 in a manner which permits their subsequent application into the openings of an ordinary outlet box. i

The end wall43 is provided with an arcuate groove 44 in its inner surface, and in this groove is arranged a suitable resistance winding 45. A pair of diametrically opposed openings 46 and 47 are provided for the passage therethrough of the bolts 29 and 30. The opening 46 lies adjacent to one end of the winding 45 so that when the bolt 29 passes therethrough the conducting washer 31 will establish contact with one end of the resistance winding. The winding 45 is so arranged that the opening 47 will be slightly spaced therefrom, but to further assure any absence of contact at this end of the winding, the washer 32 has been made of insulating material. A suitable countersinking 48 may be provided in the end 43 to accommodate the pivot point 34 of the arm 33.

It will be obvious that when the end 43 is properly positioned, the provision of the projections 37 upon the tube 36 will complete the formation of transverse slits in the casing as a whole. the projections 37 defining the ends of the slits. One arm 49 of the lever 33 is of a suitable length to project out of one of these slits; the other arm 50 is designed to slide over the winding 45.

The left-hand end 21 of the secondary winding is designed to pass through the opening 35 and to make contact with the arm 33 at the pivot point 34. The other end 21 of the secondary windin extends directly to the head of the bolt 30 as indicated in Fig. 4. An electrical circuit is thereby completed through the bolt 30, thence through the winding through the pivot point 34, the arm 50, the

resistance 45, and the washer 31, to the bolt 29. Pivotal movement of the arm 33 by manipulation of the end 49, will place more or less of the resistance 45 into the circuit.

The terminals 14 are provided with threaded bores which permit their application over the bolts 29 and 30 after the end 43 is positioned. The engagement between the terminals 14 and the bolts 29 and 30 serves to hold the end 43 in position and at the same time establishes contact between the terminals 14 and the secondary winding.

One further step remains to be performed, and lies in the application to the tube 36 of a scale 51 adjacent to the transverse slit through which the arm 49 projects. essential that this slit be properly positioned so that the arm 50 will properly override the resistance 45. With this object in view, a pair of tacks 52 are employed to simultaneously attach the scale 51 in its proper position and at the same time extend into the edge of the disc 24 and thereby hold the tube 36 in proper non-rotative position.

It will be obvious that the various constituent portions of my device are of extremely simple construction and nature, comprising in general merely circular discs. individual stampings, bolts, washers, etc. It will also be readily observed that the method of assembly is one of extreme simplicity. F r example, the winding of the coils is efiecte with great facility because of the independent construction of the bar 17. At the same time, a complete structure is provided which is both rugged, compact, and highly efiicient, being entirely devoid of unsightly or annoying projecting parts. The essential elements of the device are securely housed within the casing. the only manipulation pos'sible being that of the arm 49 which controls the output voltage.

It will be obvious that many changes in the details herein described and illustrated for the purpose ofexplaining the nature of my invention may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims. It is therefore intended that these details be interpreted as illustrative and not in a limiting sense.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is 1. For use with an electric outlet box having a pair of openings therein, a transformer device which includes a core comprising a rectangular loop, circular end discs mounted in parallel planes upon opposite ends of the loop with said ends arranged along diameters of said discs, windings associated with said core; a casing comprising a tubular body portion enclosin said core and discs, and ends for said bOf portion; a pair of terminals ex tending rom each of said ends, each pair being electrically connected with a predetermined winding within the casing; and means for securing said terminals to said ends, said means serving at the same time to secure said ends to respective discs; one of said pair of terminals comprising spaced contact prongs designed for insertion into the outlet box openings.

2. In an outlet box transformer device, a substantially cylindrical casing, a core within said casing and including a looped core portion, and an independent central core portion, the latter comprising a bar of rectangular cross-section, a pair of washers having rectangular openings therein to permit frictional application thereof over said bar, Whereby a spool is provided of said washers and the bar ortion between them, and means for associatlng the bar with the loop after desired transformer windings have been applied to said spool.

3. In an outlet box transformer device, a substantially cylindrical casing, a core therein and including a looped core portion, and an independent central core portion, the latter comprising a bar of rectangular cross-section, a pair of washers having rectangular openings therein to permit frictional application thereof over said bar, whereby a spool is provided of said washers and the bar portion between them, and said bar being of a length just sufiicient to permit frictional interposition thereof between two opposite sides of the loop, whereby desired transformer windings may be independently applied to said spool prior to the association of the latter with the loop.

4. In an outlet box transformer device, a substantially cylindrical easing, a core within the casing and comprising a looped core portion comprising a series of superposed laminations lying in the plane of the loop, and a separate central core portion comprising a laminated bar adapted to span the space between opposite sides of the loop, the laminations of the bar being arranged in planes perpendicular to that of the loop.

5. In an outlet box transformer device, a substantially cylindrical casing including end walls, a core within the casing and including a core portion comprising a rectangular loop, end discs arranged in parallel planes upon opposite ends of the loop, a central core portlon comprising a bar interposable between said opposite ends to complete the core structure, means for simultaneously securing said ends to said discs and retaining the bar 1n position, and means for securing said discs to the insides of said end walls respectively.

6. In an outlet box transformer device, a substantially cylindrical casing including end walls, a core within the casing and including a core portion comprising a rectangular loop, end discs arranged in parallel planes upon opposite ends of the loop, a central core portion comprising a bar lnterposable between said opposite ends to complete the core structure, means for simultaneously securing said ends to said discs and retaining the bar in position, said means comprising clamps engaging said ends and securable to said discs, and said clamps having portions which engage said bar; and meansfor securing said discs to the insides of said end walls respectively.

7. In an outlet box transformer device, a substantially cylindrical casing, a transformer core within said casing and including a laminated bar, a pair of washers having openings therein to permit the mounting of the washers uponthe bar, whereby said laminations are retained in position, and means for retaining the washers in predetermined spaced relationship so as to provide a spool, said means including integral struck-up portionsprovided in the outermost laminations.

8. transformer of the character described, comprising acore portion in the form of a rectangular loop, an independent central core portion comprising a bar, a pair of independent washers associated with the bar to form a spool therewith for the reception of windings, said bar being of a size to permit its frictional interposition between opposite ends of the loop after said windings arein place, a set of clamps engaging said opposite ends and having portions which engage said bar to insure its positional security, a pair of end discs attached to said clamps and arranged in parallel planes with the core portions therebetween, and a casing comprising a tubular portion which encloses both discs.

9. For use with an electric outlet box having a pair of openings therein, a transformer comprising a core in the form of a rectangular loop, a composite cylindrical casing for the core and including a separable end wall, means for securing one end of the rectangular loop to the inside of said end wall, a pair of spaced contact prongs secured to and extending from the outside of said end wall, said prongs being designed to be frictionally insertable into the openings of the outlet box, transformer windings associated with the core, and means for electrically uniting said prongs with opposite ends of the primary winding respectively.

10. For use with an electric outlet box having a pair of openings therein, a transformer comprising a core in the form of a rectangw lar loop, a disc secured to one end of the rectangular loop transversely to the plane thereof, a composite cylindrical casing for the' core and disc and including a separable end wall adapted to overlie said disc, means for securing said disc to the inside of said end wall, a pair of spaced contact prongs secured to and extending from the outside of said end wall, said prongs being designed for frictional insertion into the outlet box openings, a transformer windin associated with the core, and means extending through said disc and end wall for electrically uniting said prongs with the opposite ends respectively of said winding.

11. For use with an electric outlet box having a pair of openings therein, a transformer comprising a core in the form of a rectangular loop, a disc secured over each of opposite ends of the rectangular loop transversely to the plane thereof; a composite cylindrical casing which includes a tube applicable over the discs to enclose them and the core, and two separable end walls adapted to overlie respective discs; means for securing said end walls to respective discs so as to secure the core firmly between the end walls, a pair of spaced contact prongs secured to and extending from the outside of one end wall, said prongs being of a character to permit insertion and frictional engagement thereof into the openings of the outlet box, and a transformer winding associated with the core and having its opposite ends electrically connected with said prongs respectively.

12. For use with an electric outlet box having a pair of openings therein, a transformer comprising a core in the form of a rectangular loop, and an independent applicable central core portion interposed between opposite ends of the loop; a composite cylindrical casing for the core and including two separable end walls; means for securing the end walls to said opposite ends of the ioop, said means including a pair of spaced clamps arranged on opposite sides of the interposed central core portion; a pair of spaced contact prongs secured to' and extending from the outside of one end wall and so designed as to be frictionally insertable into the outlet box openings, transformer windings associated with the core, and means for electrically uniting said prongs with opposite ends respectively of one of said windings.

In witness whereof, I have signed and seal7ed this specification this 26 day of Feb. 192

FREDERICK CHARLES WAPPLER. 

